Brussels BRU to Zagreb ZAG flight with Ryanair

Lufthansa CityLine is a German regional airline and a wholly-owned subsidiary of Deutsche Lufthansa AG, operating as part of the Lufthansa Regional concept. Headquartered at Munich Airport, with hubs also at Frankfurt Airport, it operates a dense domestic and European network on behalf of its parent company. The airline primarily uses regional jets like the Bombardier CRJ900, along with Airbus A319s and A320neos, to connect smaller European cities to Lufthansa's major hubs. Lufthansa CityLine is known for its reliability in providing feeder traffic to Frankfurt and Munich.

Air Serbia is the national flag carrier of Serbia, with its main hub at Belgrade Nikola Tesla Airport. The airline's origins trace back to Aeroput, established in 1927, making it one of the oldest airlines in Europe. Rebranded as Air Serbia in 2013 after a partnership with Etihad Airways, the airline has since modernized its fleet and expanded its network. Air Serbia operates scheduled, seasonal, and charter flights to over 90 destinations across Europe, the Mediterranean, North America, Asia, and Africa. They offer both passenger and cargo services, and in cooperation with partner airlines, extend their reach to international destinations in Asia, Australia, North America, and Africa. The airline is a member of the International Air Transport Association (IATA).

CityJet is an Irish regional airline headquartered in Dublin, Ireland. Founded in 1992, it began operations in 1994, initially flying between Dublin and London City Airport under a franchise agreement with Virgin Atlantic. CityJet transitioned its business model in 2018, ceasing its own-brand scheduled services to focus on wet leasing aircraft to other European airlines. This means CityJet provides aircraft and crew to operate flights on behalf of other carriers. As of 2023, CityJet operates a fleet of Bombardier CRJ900 and CRJ1000 aircraft, primarily for airlines like Scandinavian Airlines (SAS), Lufthansa, and Brussels Airlines. In 2023, CityJet merged with Air Nostrum, forming the Strategic Alliance of Regional Airlines (SARA).

KLM Cityhopper is the regional airline subsidiary of KLM Royal Dutch Airlines, headquartered in Haarlemmermeer, Netherlands, and based at Amsterdam Airport Schiphol. Established in 1991 from the merger of NLM CityHopper and Netherlines, it operates scheduled European feeder services on behalf of KLM, connecting smaller cities and regional airports to KLM's main hub. As an affiliate of SkyTeam, KLM Cityhopper operates a fleet primarily consisting of Embraer E-Jet aircraft, including the Embraer 175, 190, and E195-E2 models. It serves numerous inter-European destinations, playing a vital role in KLM's regional and international network.